The exchange of packetized information in a wireless communication system has already grown dramatically and probably will also grow in the future. In some wireless telecommunications networks, it is important to track or monitor the volume of exchanged packet data and/or measure the bandwidth utilization of the packet data network and/or the telecommunications network. Where such measures are important to charging or billing a user, it is important to generate charging information as accurately as possible. Additionally, the regulatory environment in telecommunication and consumer affair organisations, are introducing increased requirements on accuracy of charging of data usage of end customers.
In an Internet Protocol based environment, respectively in Internet Protocol networks, data packets may be discarded at various network elements because of either overload situations in routers, gateways etc. and/or because of congestions on transport channels/media interconnecting these network elements. There exist packet exchange protocols and associated systems—e.g. standard TCP/IP protocol-based systems provide for accurate monitoring of and charging for data exchanged through a communications system—that provide for a verification of the packet data exchanged between two points of an Internet Protocol network that would enable the generation of accurate charging information. However, such reliable protocols impose significant overhead as compared to, for example, UDP (User Datagram Protocol) or other packet oriented protocols. Such unreliably protocols are used according to the 3GPP standards (i.e. the standards of the third generation partnership project) in mobile communication systems and hence, it is a problem for such systems to accurately charge a user for utilization of the network for data transfers.
In fixed networks, discarding of packets can be avoided or kept negligible by proper dimensioning of network equipment and transport line dimensioning. In the context of mobile telecommunications networks, e.g. cellular networks, discard of packets is most likely to happen at the termination points of the air interfaces, due to the unreliable and varying nature of the air interface. Since temporary congestion situations are originated by the unreliable and varying nature of the air interface, packet discard cannot be avoided even by proper dimensioning and configuration.
In mobile telecommunications networks, charging is done usually at hierarchically higher networks nodes like gateways. Therefore, the actual counted volume at a hierarchically higher networks nodes like a gateway, compared to the data volume arriving at the user equipment of the customer may be less, due to intermediate network equipment discarding data packets temporarily.
For 3G networks (third generation networks, especially UMTS (Universal Mobile Telecommunications System) networks), a solution to report the unsuccessfully transmitted down link user plane data volume is described in 3GPP TS 25.413. The solution can be sketched as follows:                The radio network controller (RNC) is the central element in the radio network, and furthermore the termination point of the air interface radio protocols.        Thus even in case of mobility of a user, i.e. in case the user changes from one base station (NodeB) to another, the dataflow has to pass through the radio network controller.        Therefore the radio network controller is the most suitable place to collect/count the number of undelivered/discarded packets, associated with certain bearers and allocated to a specific user equipment.        The core network may request a report about the number of unsuccessfully transmitted down link user plane data volume from the radio network controller.        
However, for radio network architectures with distributed base transceiver stations where the air interface terminates directly in the base transceiver stations such as the LTE system (Long Term Evolution), no such solution for providing improved charging information accuracy exists.